Leonardo da Vinci’s diving suit was designed to let a person breathe underwater.
Leonardo drew the suit in the early 1500s while considering naval engineering and underwater military operations. His concept included a sealed leather garment, a mask, and breathing tubes connected to the surface. Some versions of the design also show a container intended to help supply or manage air.
The suit was an idea on paper, not a documented device that Leonardo tested successfully. Long breathing tubes would have created serious problems, including limited airflow, water pressure, and the danger of the tubes being damaged. Modern diving equipment depends on technologies that were unavailable to Leonardo, such as reliable compressed-air systems.
The design is sometimes incorrectly called Leonardo’s submarine. His notebooks contain several underwater concepts, but the diving suit specifically refers to wearable equipment for a diver rather than a vehicle carrying people below the surface.